<!DOCTYPE html>
<html>
<head>
    <title>Demo for form</title>
</head>
<body>
    <form method="POST">
        username: <input type="text" name="username">
        password: <input type="password" name="password">
        <input type="submit" name="submit">
        <!-- <label>{{ msg }}</label> -->
        {% for m in get_flashed_messages() %}
            <label>{{m}}</label>
        {% endfor %}
    </form>
</body>
</html>